[vm] Follow-up changes to process_fuchsia.cc
[vm] Follow-up changes to process_fuchsia.cc

This is a follow-up to

 https://dart-review.googlesource.com/c/sdk/+/139640

Due to the lack of fuchsia builders on Dart CI this was only uncovered
by the roller.

Issue https://github.com/dart-lang/sdk/issues/41076

Change-Id: Ib2bb69aa3b6d1a12f79e544323a8bd3cefe496e0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/139810
Commit-Queue: Martin Kustermann <a35dd5b79fac84b2bb3b026a16b8becc55af5961@google.com>
Reviewed-by: Alexander Markov <239e774fd29abc1267878f57afe1a8a03e0ca887@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk